The long-term goals of this program of research on sensory gating in children is based on building a multivariate model that will help elucidate which factors contribute to measuring stable sensory gating in children and testing the model to determine if it functions similarly for children and adults. The model states that measures of sensory gating may vary from individual to individual because the outcome represents an interaction of stimulus presentation protocols, such as stimulus intensity, number of trials, and task instructions, with several trait and state variables of the participant including but not limited to maturation of prefrontal cortex and executive function (attention), alpha/ nicotinic acetylcholine receptor gene (gene abnormalities), and stress level at electroencephalography (EEC) testing (noradrenergic tone). The proposed project will contribute to understanding the role of attention in this model of sensory gating. The three specific aims of the project are: 1) To determine if the manipulation of attention will differentially effect sensory gating in adults and children; 2) To demonstrate that the developmental nature of attention coincides with changes in levels of sensory gating in children; and 3) To determine the split-half and test-retest reliability measures of sensory gating in children and adults. The research design entails assessing 40 young adults and 40 children, ages 6 to 12 years, during two visits. EEC data will be collected using 3 variations of the Sensory Gating event-related potential (ERP) paradigm which manipulate the focus of attention. One version will be used twice, once on each visit, in order to obtain test-retest reliability measures. To investigate maturation of attention in children and its relationship to changes in sensory gating performance, several behavioral measures of attention will be obtained. The health related impact of the project is a better understanding of the variability in sensory gating measures observed in children. Such knowledge will lead to more reliable and objective measures of the brain's ability and inability to gate sensory information which will allow valid early identification of neurodevelopmental disorders such as in schizophrenia and autism. Improved measures of sensory gating may lead to productive and cost efficient studies assessing treatment effectiveness. [unreadable] [unreadable] [unreadable]